Expression of vascular endothelial growth factor in capillary hemangioblastoma

The gene expression of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, was examined in capillary hemangioblastomas which are composed of abundant microvasculature and primitive angiogenic elements represented by stromal cells. Northern blot and in situ hybridization analyses showed that the VEGF mRNA was highly expressed in the stromal cells, but not in the endothelial cells. Reverse transcription/PCR analysis revealed that the VEGF mRNA species expressed in the stromal cells were the shorter splicing forms, VEGF121 and VEGF165, which are potent to be secreted from cells and the longer splicing form, VEGF189, which is predominantly cell-associated. Our findings suggest that VEGF secreted from the stromal cells plays an important role in the endothelial cell proliferation in capillary hemangioblastomas.